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Open Access Case Report

Powassan virus infection: case series and literature review from a single institution

Mihir Raval12*, Mayank Singhal12, Dubert Guerrero12 and Augusto Alonto12

Author Affiliations

1 Sanford Hospital, Fargo, ND, USA

2 Internal Medicine, Department of Internal Medicine, University of North Dakota, Sanford Health System, 801, Broadway North, Fargo, ND, 58122-0170, USA

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BMC Research Notes 2012, 5:594  doi:10.1186/1756-0500-5-594

Published: 30 October 2012



Powassan virus is a flavivirus related to eastern hemisphere’s tick-borne encephalitis viruses. It can cause a rare but potentially life-threatening disease including encephalitis.

Case presentation

We report four cases of POWV infection in Minnesota and North Dakota with known exposure to tick bites in 2011. Our first case was an 18-year-old male who dramatically presented with seizure and headache with positive serum analysis for Powassan virus immunoglobulin M. The second case was a 60 year old gentleman with intraparenchymal hemorrhage and was diagnosed via cerebrospinal fluid analysis. Thirdly, a 61 year old male developed altered mental status and encephalitis. Our fourth patient was a 69 year old male who had headache and non-focal weakness who was diagnosed with serum analysis.


Symptoms of Powassan virus infection ranged from headaches to seizures and severe neurological symptoms. This study serves to highlight the increased detection of Powassan virus infection in the central north United States. This report focuses on the increasing incidence that can lead to increasing efforts for raising awareness regarding this infection. There is a need for clinician vigilance and public attention due to its increasing detection, westward progression and varied clinical presentations.

Powassan Virus encephalitis; Tick borne encephalitis; Intraparenchymal hemorrhage; Seizures